Anti-interference electricity equipment and power supply system
By using series normally open contacts and independent anti-shaking controllers in the electrical power supply system, the problem of high cost of anti-shaking devices of energy storage power supply is solved, and the low-cost anti-shaking function is achieved, and the system reliability and robustness are improved.
Patent Information
- Application Number
- CN202510679097.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-26
- Publication Date
- 2025-07-18
AI Technical Summary
In the prior art, the initial investment and operation and maintenance costs of energy storage power-type anti-shaking devices are high and occupy space, resulting in unplanned shutdowns in continuous production enterprises such as petrochemical or metallurgy when the power grid is instantly shaken, causing economic losses and safety hazards.
The first normally open contact and the second normally open contact are connected in series, and are connected in parallel at both ends of the zero-non-non contact. The two independent anti-swing controllers detect the shaking and control the closure of the contacts to realize the anti-swing function and reduce the cost of the equipment.
The anti-shaking function can be achieved without the need for energy storage power supply, reducing equipment costs, and improving the robustness and reliability of the system, reducing the risk of unplanned downtime.
Smart Images
Figure CN120342052A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of electrical technology, and particularly to an anti - power - fluctuation device and a power supply system. Background Art
[0002] In continuous production enterprises such as petrochemical or metallurgical industries, when encountering power - voltage sags or momentary voltage losses such as short - circuit faults, momentary "power fluctuations" in the power grid, dual - power switching, backup power - on self - closing or reclosing operations, the contactors running in the motor circuit will release, causing unplanned shutdown of production, resulting in a large amount of economic losses and safety hazards. To solve the above problems, in the prior art, energy - storage power - type anti - power - fluctuation devices such as storage batteries or supercapacitors can be set up. When the system voltage sags or loses voltage, they supply power to the load instead of the grid power supply.
[0003] However, the initial investment and operation and maintenance costs of the energy - storage power - type anti - power - fluctuation device are both very high, and the device itself occupies a certain area, further increasing the investment cost. Summary of the Invention
[0004] The purpose of the present invention is to provide an anti - power - fluctuation device and a power supply system to at least partially solve the above problems of the prior art.
[0005] To achieve the above purpose, on the one hand, the present invention provides an anti - power - fluctuation device, which is applied to the start - stop control loop of an electrical appliance power supply system. The start - stop control loop is used to control the opening and closing of the power supply switch of the electrical appliance. The start - stop control loop includes a contactor. The contactor includes a contactor coil, a main contact as the power supply switch, and a first normally - open contact. When the first normally - open contact is closed, the contactor coil is energized, the main contact is closed, and the electrical appliance is energized; after the first normally - open contact is opened, the contactor coil loses power, the main contact is opened, and the electrical appliance loses power. The anti - power - fluctuation device includes:
[0006] A series - connected first normally - open contact and a second normally - open contact, which are connected in parallel across the two ends of the first normally - open contact.
[0007] A first anti - power - fluctuation controller, which is used to detect whether power fluctuation occurs at the first normally - open contact, and when detecting that power fluctuation occurs, controls the first normally - open contact to close;
[0008] A second anti - power - fluctuation controller, which is used to detect whether power fluctuation occurs at the first normally - open contact, and when detecting that power fluctuation occurs, controls the second normally - open contact to close.
[0009] Preferably, the anti - power - fluctuation device further includes:
[0010] A first second - normally - open contact and a second second - normally - open contact, which are respectively connected to the on - line monitoring cabinet of the anti - power - fluctuation device;
[0011] The first anti - power - fluctuation controller is further configured to control the first two - normally - open contacts to close when power - fluctuation is detected.
[0012] The second anti - power - fluctuation controller is further configured to control the second two - normally - open contacts to close when power - fluctuation is detected.
[0013] The on - line monitoring cabinet of the anti - power - fluctuation device is configured to send a reminder signal when the first two - normally - open contacts close and / or the second two - normally - open contacts close.
[0014] Preferably, the on - line monitoring cabinet of the anti - power - fluctuation device includes an on - line monitoring circuit. The on - line monitoring circuit includes a first circuit, a second circuit, and a third circuit connected in parallel. The first circuit includes a coil of a first relay and the first two - normally - open contacts connected in series. The second circuit includes a normally - closed contact of the first relay and a first indicator light. The third circuit includes a normally - open contact of the first relay and a second indicator light.
[0015] Preferably, the on - line monitoring cabinet of the anti - power - fluctuation device includes an on - line monitoring circuit. The on - line monitoring circuit includes a first circuit, a second circuit, and a third circuit connected in parallel. In the first circuit, the first two - normally - open contacts and the second two - normally - open contacts are connected in parallel and then connected in series with the coil of the first relay. The second circuit includes a normally - closed contact of the first relay and a first indicator light. The third circuit includes a normally - open contact of the first relay and a second indicator light.
[0016] Preferably, when the second indicator light is constantly on, it indicates a failure of the anti - power - fluctuation device.
[0017] Preferably, it further includes a communication screen connected to the on - line monitoring cabinet of the anti - power - fluctuation device. When the second indicator light is constantly on, the on - line monitoring cabinet of the anti - power - fluctuation device sends a notification signal to the communication screen.
[0018] The communication screen is configured to send a fault alarm signal to the control room according to a preset path after receiving the notification signal.
[0019] Preferably, it further includes a remote control system DCS circuit. The DCS circuit includes a zeroth two - normally - open contact of the contactor connected in series with a DCS controller, and a first three - normally - open contact and a second three - normally - open contact connected in series and then connected in parallel with the zeroth two - normally - open contact. The first anti - power - fluctuation controller is further configured to control the first three - normally - open contacts to close when power - fluctuation is detected. The second anti - power - fluctuation controller is further configured to control the second three - normally - open contacts to close when power - fluctuation is detected.
[0020] Preferably, the first anti-power-sag controller includes a first power-sag identification chip, and the second anti-power-sag controller includes a second power-sag identification chip. The first power-sag identification chip and the second power-sag identification chip are used to detect whether power sags occur at the first normally-open contact respectively.
[0021] On the other hand, the present invention provides a power supply system, including a power supply circuit for an electrical appliance and a start-stop control circuit. The start-stop control circuit is used to control the opening and closing of a power supply switch of the electrical appliance in the power supply circuit. The start-stop control circuit includes a contactor. The contactor includes a contactor coil, a main contact serving as the power supply switch, and a first normally-open contact. When the first normally-open contact is closed, the contactor coil is energized, the main contact is closed, and the electrical appliance is powered on; after the first normally-open contact is opened, the contactor coil loses power, the main contact is opened, and the electrical appliance loses power; the start-stop control circuit includes the anti-power-sag device provided in the above aspect.
[0022] Preferably, the start-stop control circuit further includes: a manual start-stop circuit and a DCS start-stop circuit.
[0023] Compared with the prior art, the present invention has at least the following advantages:
[0024] By adopting the anti-power-sag device provided in this embodiment, two independent anti-power-sag controllers are used to detect the occurrence of power sags respectively, and then the normally-open contact is closed to achieve the anti-power-sag function. The anti-power-sag function can be realized without a energy storage power supply type anti-power-sag device, reducing the equipment cost. Moreover, two independent anti-power-sag controllers are used for control, and the probability that the two anti-power-sag controllers fail simultaneously is almost 0. Therefore, it is impossible for the two normally-open contacts to be closed simultaneously, with high robustness and strong reliability. Description of the Drawings
[0025] Figure 1 It is a schematic structural diagram of the electrical appliance power supply system provided by the embodiment of the present invention.
[0026] Figure 2 It is a schematic structural diagram of the anti-power-sag device on-line monitoring cabinet provided by the embodiment of the present invention.
[0027] Figure 3 It is another schematic structural diagram of the anti-power-sag device on-line monitoring cabinet provided by the embodiment of the present invention.
[0028] Figure 4 It is a schematic structural diagram of the anti-power-sag device provided by the embodiment of the present invention. Detailed Embodiments
[0029] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the scope of protection of the present invention.
[0030] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so as to understand the embodiments of the present invention described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a product or device including a series of units does not necessarily have to be limited to those units clearly listed, but may include other units not clearly listed or inherent to these products or devices.
[0031] In the present invention, the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal", etc. is based on the orientation or positional relationship shown in the accompanying drawings. These terms are mainly used to better describe the present invention and its embodiments, and are not used to limit that the indicated devices, elements or components must have a specific orientation, or be constructed and operated in a specific orientation.
[0032] Moreover, in addition to being able to represent an orientation or positional relationship, some of the above terms may also be used to represent other meanings. For example, the term "upper" may also be used to represent a certain attachment relationship or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in the present invention can be understood according to specific circumstances.
[0033] In addition, the terms "installed", "set", "provided with", "connected", "connected to", "socketed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or there can also be internal communication between two devices, elements or components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0034] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the drawings and in conjunction with the embodiments.
[0035] Example 1
[0036] This embodiment provides an anti - power - sway device, which is applied to the start - stop control circuit of an electrical appliance power supply system. The start - stop control circuit is used to control the opening and closing of the power supply switch of the electrical appliance.
[0037] Figure 1 The structural schematic diagram of the electrical appliance power supply system is shown. Refer to Figure 1 As shown, the start - stop control circuit includes a contactor. The contactor includes a contactor coil 10, a main contact 100 as the power supply switch, and a first normally - open contact 101. When the first normally - open contact 101 is closed, the contactor coil 10 is energized, the main contact 100 is closed, and the electrical appliance is energized; after the first normally - open contact 101 is opened, the contactor coil 10 loses power, the main contact 100 is opened, and the electrical appliance loses power.
[0038] The anti - power - sway device includes:
[0039] A series - connected first normally - open contact 111 and a second normally - open contact 121, which are connected in parallel across the two ends of the first normally - open contact 101;
[0040] A first anti - power - sway controller, which is used to detect whether power sway occurs at the first normally - open contact 101, and when power sway is detected, control the first normally - open contact 111 to close;
[0041] A second anti - power - sway controller, which is used to detect whether power sway occurs at the first normally - open contact 101, and when power sway is detected, control the second normally - open contact 121 to close.
[0042] With the anti - power - sway device provided in this embodiment, when power sway occurs, the normally - open contacts 111 and 121 are closed, so that the contactor coil circuit continues to be energized, thus ensuring the normal operation of the electrical appliance.
[0043] In one implementation, as shown in Figure 1 The anti - power - sway device provided in this embodiment may further include:
[0044] A first second - normally - open contact 112 and a second second - normally - open contact 122, which are respectively connected to the on - line monitoring cabinet of the anti - power - sway device;
[0045] The first anti - power - sway controller is further used to control the first second - normally - open contact 112 to close when power sway is detected;
[0046] The second anti - power - sway controller is further used to control the second second - normally - open contact 122 to close when power sway is detected;
[0047] The online monitoring cabinet for anti - power - sway equipment is used to send a reminder signal when the first double - normally - open contact 112 and / or the second double - normally - open contact 122 is closed.
[0048] In one embodiment, refer to Figure 2 the structural schematic diagram of the online monitoring cabinet for anti - power - sway equipment shown. The online monitoring cabinet for anti - power - sway equipment includes an online monitoring circuit. The online monitoring circuit includes a first circuit, a second circuit, and a third circuit connected in parallel. In the first circuit, the first double - normally - open contact 112 and the second double - normally - open contact 122 are connected in parallel and then connected in series with the coil KA1 of the first relay. The second circuit includes the normally - closed contact KA11 of the first relay and the first indicator light HG1. The third circuit includes the normally - open contact KA12 of the first relay and the second indicator light HR1. As Figure 2 shown, the online monitoring cabinet for anti - power - sway equipment can monitor multiple anti - power - sway equipment simultaneously. Figure 2 Among them, KHD21 and KHD22 belong to another anti - power - sway equipment, and the indicator lights HG2 and HR2, the relay coil KA2 and its contacts KA21 and KA22 are used in a supporting manner.
[0049] For example, HG1 is a green indicator light and HR1 is a red indicator light, and the indicator lights are all installed on the cabinet surface of the monitoring cabinet. (1) When the grid voltage is normal, the anti - power - sway equipment does not operate, the contacts 112 and 122 are both in the open state, and the contacts of KA1 all maintain their initial states. At this time, the HG1 circuit is connected and the HR1 circuit is disconnected, and HG1 lights up, that is, the green indicator light is on, indicating that the grid voltage is normal at this time. (2) When a power sway occurs in the grid, the anti - power - sway equipment operates, the contacts 112 and 122 are both in the closed state, the normally - open contact of KA1 closes and the normally - closed contact opens. At this time, the HG1 circuit is disconnected and the HR1 circuit is connected, and HR1 lights up, that is, the red indicator light is on. However, the time of the power sway is very short. After the power sway is completed, the grid voltage immediately returns to normal. At this time, the circuit returns to the initial state again, that is, the green light is on and the red light is off. If someone observes the above state, that is, the red light briefly lights up and then goes out, it indicates that a power sway has occurred. (3) When a certain controller of the anti - power - sway equipment fails, the contact controlled by this controller operates, that is, the contact 112 or 122 changes to the closed state, the normally - open contact of KA1 closes and the normally - closed contact opens. At this time, the HG1 circuit is disconnected and the HR1 circuit is connected, and HR1 lights up, that is, the red indicator light is on. Different from (2), when the anti - power - sway equipment fails, it usually cannot recover by itself. Therefore, this red indicator light will always be on, and the green light will always be off. When the observer finds that the red indicator light is always on, they can know that the anti - power - sway equipment has failed.
[0050] In another embodiment, refer to Figure 3Schematic diagram of the structure of the online monitoring cabinet for anti-power-sag equipment. The online monitoring cabinet for anti-power-sag equipment includes an online monitoring circuit. The online monitoring circuit includes a first circuit, a second circuit, and a third circuit connected in parallel. The first circuit includes a coil KA1 of a first relay and a first two-normally-open contact 112 connected in series. The second circuit includes a normally-closed contact KA11 of the first relay and a first indicator light HG1. The third circuit includes a normally-open contact KA12 of the first relay and a second indicator light HR1. Refer to Figure 3 As shown, the online monitoring circuit includes a fourth circuit, a fifth circuit, and a sixth circuit connected in parallel. The fourth circuit includes a coil KA2 of a second relay and a second two-normally-open contact 122 connected in series. The fifth circuit includes a normally-closed contact KA21 of the second relay and a third indicator light HG2. The sixth circuit includes a normally-open contact KA22 of the second relay and a fourth indicator light HR2. Figure 3 The shown online monitoring cabinet for anti-power-sag equipment can also monitor multiple anti-power-sag equipment at the same time, that is, two groups of four indicator lights are used to monitor one anti-power-sag equipment.
[0051] At this time, the online monitoring cabinet for anti-power-sag equipment can also give a fault prompt by the constant illumination of the red light, which is different from Figure 2 the situation. Since each red light corresponds to an anti-power-sag controller of the anti-power-sag equipment, it is possible to directly know which anti-power-sag controller has failed.
[0052] In one embodiment, the anti-power-sag equipment further includes a communication screen connected to the online monitoring cabinet for anti-power-sag equipment. When the HR indicator light is constantly on, the online monitoring cabinet for anti-power-sag equipment sends a notification signal to the communication screen; the communication screen is used to send a fault alarm signal to the control room according to a preset path after receiving the notification signal. Figure 4 Schematic diagram of the structure of the anti-power-sag equipment is shown. Among them, KHD1 represents the first anti-power-sag equipment, KHD2 represents the second anti-power-sag equipment, and correspondingly, KHDN represents the Nth anti-power-sag equipment. The online monitoring cabinet for anti-power-sag equipment includes a PLC (Programmable Logic Controller). The communication screen can include, for example, a communication management machine, a switch, and an optical-electric converter, and gives an alarm through sound, light, and other means. The control room can be, for example, a preset manned substation, so as to give an alarm to the duty personnel in time.
[0053] In one embodiment, the anti-power-sag equipment further includes a remote control system DCS circuit. Refer to Figure 1As shown, the DCS circuit includes the zeroth two normally open contacts 102 of the contactor in series with the DCS controller, and the first three normally open contacts 113 and the second three normally open contacts 123 that are in series and then in parallel with the zeroth two normally open contacts 102; the first anti-power-sag controller is further configured to control the first three normally open contacts 113 to close when detecting a power sag; the second anti-power-sag controller is further configured to control the second three normally open contacts 123 to close when detecting a power sag.
[0054] Wherein, the first anti-power-sag controller includes a first power-sag identification chip, the second anti-power-sag controller includes a second power-sag identification chip, and the first power-sag identification chip and the second power-sag identification chip are configured to respectively detect whether a power sag occurs in the zeroth one normally open contact.
[0055] The power-sag identification chip is generally used to detect instantaneous voltage fluctuations in the power grid (such as voltage sags, swells, interruptions, etc.) and make a quick response to protect sensitive equipment from damage. Its core working principle includes three stages: signal acquisition, analysis and judgment, and output control. By real-time monitoring parameters such as voltage amplitude (detecting voltage sags and swells), frequency (detecting power grid frequency fluctuations), phase angle (detecting phase jumps), and duration (judging the severity of the power-sag event), and comparing them with set thresholds, etc., and making logical judgments, it can identify whether a power sag occurs. The power-sag identification chip is a prior art, and this patent will not elaborate on it.
[0056] It should be noted that as long as the circuit control function in the embodiments of the present invention can be achieved, normally closed contacts can be used to replace the normally open contacts in this embodiment, and this patent does not limit this.
[0057] By adopting the anti-power-sag device provided in this embodiment, two independent anti-power-sag controllers are used to respectively detect the occurrence of anti-power-sag, and then the normally open contacts are closed to achieve the anti-power-sag function. The anti-power-sag function can be achieved without a energy storage power-sag device, reducing the equipment cost. Moreover, with two independent anti-power-sag controllers for control, the probability that the two anti-power-sag controllers fail simultaneously is almost 0. Therefore, it is impossible for the two normally open contacts to close simultaneously, with high robustness and strong reliability.
[0058] Embodiment 2
[0059] This embodiment provides a power supply system, including a power supply circuit for an electrical appliance and a start-stop control circuit. The start-stop control circuit is used to control the opening and closing of the power supply switch of the electrical appliance in the power supply circuit. The start-stop control circuit includes a contactor. The contactor includes a contactor coil, a main contact serving as the power supply switch, and a first normally open contact. When the first normally open contact is closed, the contactor coil is energized, the main contact is closed, and the electrical appliance is powered on. After the first normally open contact is opened, the contactor coil loses power, the main contact is opened, and the electrical appliance loses power. The start-stop control circuit includes the anti-voltage-sag device described in Embodiment 1 and any of its embodiments.
[0060] Figure 1 The structural schematic diagram of the power supply system is shown. As Figure 1 shown, the descriptions of each component are as follows:
[0061] FU: Fuse, used to implement short-circuit protection for the circuit.
[0062] SA: Local / remote transfer switch, usually installed on the local operation column, used to achieve the switching between local and remote starting of the motor. When switched to the local gear, the motor can only be started locally; when switched to the remote gear, the motor can only be started by the remote DCS.
[0063] SB1: Start button, installed on the local operation column, used to achieve the local start of the motor.
[0064] SB2: Stop button, installed on the local operation column, used to achieve the local stop of the motor.
[0065] R1: Normally open contact of the intermediate relay, installed in the remote DCS system, used to achieve the remote start of the motor.
[0066] R2: Normally closed contact of the intermediate relay, installed in the remote DCS system, used to achieve the remote stop of the motor.
[0067] FR: Thermal relay, used to achieve the overload protection of the motor. Its main body is connected in series in the main circuit of the motor, and its normally closed contact is connected in series in the control circuit of the motor. When the motor is overloaded, the normally closed contact of the thermal relay opens, cutting off the contactor circuit in the control circuit, the contactor coil loses power, the main contact of the contactor disconnects, and the motor stops.
[0068] Contactor: It is used to start and stop the motor. Its main contact 100 is connected in series in the main circuit of the motor, and its coil 10 is connected in series in the control circuit of the motor. When the coil 10 is de-energized, the main contact 100 is in the open state, and the motor is de-energized and in the stop state; when the coil 10 is energized and attracted, the main contact 100 turns to the closed state, and the motor starts after being energized. At the same time, a normally open contact 101 of this contactor is connected in parallel at both ends of the "local start button" and the "remote start normally open contact" as the self-holding contact of the contactor. When the contactor coil 10 is energized, this self-holding contact 101 closes. Since the "local start button" and the "remote start normally open contact" will immediately disconnect after closing, the subsequent coil circuit of the contactor can only be energized and maintained in the attracted state by the self-holding contact 101. Another normally open contact 102 of the contactor is connected to the remote DCS system. Through the state of this contact, the DCS can know the operating state of the motor.
[0069] Power-sag resistant device KHD: The power-sag resistant device includes two power-sag resistant controllers ( Figure 1 not shown in the figure), the first power-sag resistant controller controls switches 111, 112 and 113, and the second power-sag resistant controller controls switches 121, 122 and 123. Switches 111 and 121 are connected in parallel at both ends of the contactor self-holding contact 101. When a power sag occurs, the power supply voltage drops or disappears, the contactor coil 10 loses power, the contact 101 opens, and the power-sag resistant device can judge that a power sag has occurred in a very short time and closes its normally open contacts 111 and 121, and the contactor coil 10 is re-energized. Since the disconnection time of the contactor is very short, the motor can keep running without stopping due to inertia. Switches 112 and 122 are respectively connected to the on-line monitoring cabinet of the power-sag resistant device. As described in the above Embodiment 1, they are used for the on-line monitoring cabinet of the power-sag resistant device to monitor whether the power-sag resistant device fails. Switches 113 and 123 are connected in parallel at both ends of the contactor normally open contact 102, and the combined signal is sent to the remote DCS system. The function of this contact is that when a power sag occurs, the contactor will instantaneously disconnect, and the contactor normally open contact 102 will open. At this time, the DCS will judge that the motor has stopped running and issue a command to start the standby motor; when the contacts 113 and 123 of the power-sag resistant device are connected in parallel, the DCS always receives a closed command when a power sag occurs, avoiding the DCS misjudging that the motor has stopped running and starting the standby motor.
[0070] By adopting the power supply system provided in this embodiment, the power-sag resistant function is realized through the power-sag resistant device. The power-sag resistant function can be realized without a energy storage power supply type power-sag resistant device, reducing the equipment cost. Moreover, the power-sag resistant device is controlled by two independent power-sag resistant controllers. The probability that the two power-sag resistant controllers fail simultaneously is almost 0. Therefore, it is impossible for the two normally open contacts to close simultaneously, with high robustness and strong reliability.
[0071] Finally, it should be pointed out that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Those of ordinary skill in the art should understand that the technical solutions described in the foregoing embodiments may be modified, or some of the technical features may be equivalently replaced; these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. An anti-voltage-sag device is applied to the start-stop control circuit of an electrical appliance power supply system. The start-stop control circuit is used to control the opening and closing of the power supply switch of the electrical appliance. The start-stop control circuit includes a contactor. The contactor includes a contactor coil, a main contact serving as the power supply switch, and a first normally open contact. When the first normally open contact is closed, the contactor coil is energized, the main contact is closed, and the electrical appliance is powered on; After the first normally open contact is opened, the contactor coil loses power, the main contact is opened, and the electrical appliance loses power; characterized in that, The anti-voltage-sag device includes: The first normally open contact and the second normally open contact connected in series, and are connected in parallel at both ends of the first normally open contact; The first anti-voltage-sag controller is used to detect whether voltage sag occurs at the first normally open contact, and when detecting that voltage sag occurs, control the first normally open contact to close; The second anti-voltage-sag controller is used to detect whether voltage sag occurs at the first normally open contact, and when detecting that voltage sag occurs, control the second normally open contact to close.
2. The anti-power-flicker device according to claim 1, characterized in that, The anti-voltage-sag device further includes: The first normally closed contact and the second normally closed contact are respectively connected to the on-line monitoring cabinet of the anti-voltage-sag device; The first anti-voltage-sag controller is further used to control the first normally closed contact to close when detecting that voltage sag occurs; The second anti-voltage-sag controller is further used to control the second normally closed contact to close when detecting that voltage sag occurs; The on-line monitoring cabinet of the anti-voltage-sag device is used to send a reminder signal when the first normally closed contact is closed and / or the second normally closed contact is closed.
3. The anti - power - outage - fluctuation device according to claim 2, characterized in that, The on-line monitoring cabinet of the anti-voltage-sag device includes an on-line monitoring circuit, and the on-line monitoring circuit includes a first circuit, a second circuit and a third circuit connected in parallel. The first circuit includes a coil of a first relay and a first normally closed contact connected in series. The second circuit includes a normally closed contact of the first relay and a first indicator light. The third circuit includes a normally open contact of the first relay and a second indicator light.
4. The anti-power-flicker device according to claim 2, wherein The on-line monitoring cabinet of the anti-voltage-sag device includes an on-line monitoring circuit, and the on-line monitoring circuit includes a first circuit, a second circuit and a third circuit connected in parallel; in the first circuit, the first normally closed contact and the second normally closed contact are connected in parallel and then connected in series with the coil of the first relay; the second circuit includes a normally closed contact of the first relay and a first indicator light; the third circuit includes a normally open contact of the first relay and a second indicator light.
5. The anti-power-flicker device according to claim 3 or 4, characterized in that, When the second indicator light is always on, it indicates that the anti-voltage-sag device is faulty.
6. The anti-power-flicker device according to claim 5, characterized in that, It further includes a communication screen connected to the on-line monitoring cabinet of the anti-voltage-sag device. When the second indicator light is always on, the on-line monitoring cabinet of the anti-voltage-sag device sends a notification signal to the communication screen; The communication screen is used to send a fault alarm signal to the control room according to a preset path after receiving the notification signal.
7. The anti-power-sag device according to any one of claims 1-4, characterized in that, It further includes a remote control system DCS circuit. The DCS circuit includes a second normally open contact of the contactor connected in series with a DCS controller, and a first normally open contact and a second normally open contact connected in series and then connected in parallel with the second normally open contact; the first anti-voltage-sag controller is further used to control the first normally open contact to close when detecting that voltage sag occurs; the second anti-voltage-sag controller is further used to control the second normally open contact to close when detecting that voltage sag occurs.
8. The anti-power-sag device according to any one of claims 1-4, characterized in that, The first anti-power-flicker controller includes a first power-flicker identification chip, the second anti-power-flicker controller includes a second power-flicker identification chip, and the first power-flicker identification chip and the second power-flicker identification chip are used to respectively detect whether power flicker occurs in the first normally open contact.
9. A power supply system, comprising a power supply circuit of an electrical appliance and a start-stop control circuit. The start-stop control circuit is used to control the opening and closing of a power supply switch of the electrical appliance in the power supply circuit. The start-stop control circuit includes a contactor. The contactor includes a contactor coil, a main contact serving as the power supply switch, and a first normally open contact. When the first normally open contact is closed, the contactor coil is energized, the main contact is closed, and the electrical appliance is powered on; after the first normally open contact is opened, the contactor coil loses power, the main contact is opened, and the electrical appliance loses power. The start-stop control circuit includes an anti-power-flicker device according to any one of claims 1-8.
10. The power supply system according to claim 9, wherein The start-stop control circuit further includes: a manual start-stop circuit and a DCS start-stop circuit.